Can Fish Contain Worms?

Can Fish Contain Worms? Anisakid roundworms are the most common parasite found in marine fishes. Other names for these threadlike nematodes are herring worms, cod worms and seal worms. Freshwater perch, trout, and salmon (that spend part of their life in freshwater), may carry the tapeworm larvae of Diphyllobothrium. Which fish has worms? Roundworms, called